Conventionally, a workpiece loading and unloading apparatus 201, which loads workpieces into a plate member working machine, such as a turret punch press and a laser working machine, and unloads the processed workpieces from the plate member working machine, has, as shown in FIG. 5, a stand-type main body frame 203, and a material pallet 205 on which workpieces W are stored is disposed on an upper portion on a front side (left side in FIG. 5) of the main body frame 203 so as to be capable of moving in a front-and-rear direction (right-and-left direction in FIG. 5).
A product pallet 207 on which the workpieces processed by the plate member working machine, namely, products G are stored is disposed on a lower portion on the front side of the main body frame 203 so as to be capable of moving up and down by means of a hydraulic lifter 209.
A loader 211, which is capable of moving to the plate member working machine (moving to a direction intersecting perpendicularly to a paper surface in FIG. 5), is disposed on the front side (left side in FIG. 5) of an upper frame 203U of the main body frame 203. The loader 211 is composed of a slider 213 and a workpiece carrier 215 which are capable of moving to the plate member working machine, and an air cylinder 217 as the workpiece carrier 215 is mounted to the slider 213.
An absorption frame 221 is disposed at a lower end of a piston rod 219 mounted to the air cylinder 217, and a plurality of absorption pads 223 are disposed on the absorption frame 221.
In addition, an unloader 225 having an unloader clamp (not shown) is provided on the front side (left side in FIG. 5) of the upper frame 203 of the main body frame 203 so as to be capable of moving to the plate member working machine.
According to the above constitution, when the workpiece W is loaded into the plate member working machine, the air cylinder 217 is operated, the piston rod 219 is lowered and the one workpiece W on the material pallet 205 is absorbed by the absorption pads 223. Next, after the piston rod 219 is lifted to its original position, the slider 213 of the loader 211 is moved to the plate member working machine, namely, an inner side of a direction intersecting perpendicularly to the paper surface in FIG. 5.
When the absorption pads 223 reach a position above a table of the plate member working machine, the movement of the slider 213 is stopped, and when the piston rod 219 is lowered by the operation of the air cylinder 217 and the absorption pads 223 are released, the workpiece W is put onto the table of the plate member working machine.
The workpiece W put onto the table of the plate member working machine is clamped by a workpiece clamp and moved and located so as to undergo desired plate member processing. While the workpiece W is undergoing the plate member processing, the slider 213 of the loader 211 is returned to its original position, and the unloader 225 is moved to the plate member working machine. Moreover, the material pallet 205 is moved to the right side in FIG. 5, and the product pallet 207 is lifted by the operation of the hydraulic lifter 209.
After the product G which underwent the plate member processed by means of the plate member working machine is clamped by the unloader clamp, the unloader 225 is returned to the original position, and the product G is located in a position above the product pallet 207 in FIG. 5. Next, when being unclamped from the unloader clamp, the product G is placed on the product pallet 207.
When a next workpiece W is processed, after the product pallet 207 is lowered by the operation of the hydraulic lifter 209 and the material pallet 205 is moved to the left side in FIG. 5 to be returned to the original position, the steps thereafter are repeated in the above-mentioned manner so that a lot of workpieces W undergo the plate member processing.
Incidentally, in the conventional workpiece loading and unloading apparatus 201, since the workpiece W on the material pallet 205 and the product G on the product pallet 207 are positioned up and down on the front side of the main body frame 203, there arises a problem such that a pass line is high and thus it is difficult to use this apparatus at the time of off-line.
In addition, when a workpiece W is loaded into the plate member working machine, it is necessary to move the material pallet 205 to the front and rear and to move up and down the product pallet 207. For this reason, the operation for loading and unloading the workpiece W is complicated, and it takes a long time to load and unload one workpiece W.
Furthermore, in the conventional workpiece loading and unloading apparatus 201, since a countermeasure against the case where a workpiece is processed in an emergency is not taken, it is difficult for the apparatus to cope with this situation.
Therefore, an object of the present invention is to provide a workpiece loading and unloading apparatus which is easily used at the time of off-line, and in which a time required for preparing a workpiece is shortened and interruption by another urgent workpiece which requires plate member processing is possible.